Three Generational Study We proposes to study intergenerational transmission of alcohol, tobacco, and other drug use (ATOD) across three generations (G1, G2, and G3). We will use children in the Three Generational Study (3GS), a community sample consisting of up to two of the biological children (G3) of at-risk early adult men (G2) in the Oregon Youth Study (OYS). Multiple indicators of ATOD in G3 will be assessed, including age of onset of use and growth in use over early to midadolescence. A dynamic developmental systems approach focusing on both general pathway psychopathology and outcome-specific risk factors will be used to examine the developmental pathways of precursors (e.g., ATOD awareness) and of the emergence of these behaviors from early childhood to adolescence. Hypotheses regarding cross-generational congruence in the onset and growth of ATOD also will be examined, as well as the transmission of contextual risk and problematic behaviors across three generations, and parenting behaviors and peer influences across two generations. Additionally, the role of ATOD in the etiology of three public health problems; namely health-risking sexual behavior, suicidal thoughts and behaviors, and dating violence will be tested. The OYS men show high levels of antisocial behavior (at age 25 years, 42% had two or more arrests) and substance use (estimated 50% lifetime diagnoses for alcohol dependence or abuse and 50% prevalence of marijuana use in the mid 20s). The men are currently ages 36-38 years and, with their parents (G1), have been involved in the OYS since the G2 men were ages 9-10 years. Specific Aims will be addressed through the collection and analysis of data that will expand the sample size for the early time points (ages 3 to 11 years) and extend the study to ages 19-20 years. Additionally, we will undertake secondary data analysis of the OYS, OYS-Couples Study, and 3GS extant data sets from the beginning of the proposed study period.